Oil level gauge



FIG. 1 is a perspective view of the front, right and top of an oil level gauge showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom view thereof;

FIG. 8 is an enlarged view of the portion 8 shown in FIG. 2 thereof; and,

FIG. 9 is an enlarged view of the portion 9 shown in FIG. 6 thereof.

The elements shown in broken lines are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for an oil level gauge, as shown and described. 